Figure 3.

Extrinsic noise can shape the distributions of concentrations and copy numbers. The distributions of concentrations (black) and copy numbers (gray) are shown for a stable molecule synthesized by a zero order reaction for different values of the synthesis rate k_s (Eq. 20). (A) Distributions without extrinsic noise. (B) Extrinsic noise in the synthesis rate, k_s. Extrinsic noise was modeled with a log-normal distribution of k with squared coefficient of variation of 0.1 and an autocorrelation time that much exceeds one generation time such that the resulting distributions are mixture distributions of the distributions obtained for different values of k_s drawn from the log-normal distribution. (Insets) Fits of the concentration and copy number distributions with intermediate k_s to normal (green), log-normal (blue), and gamma (red) distributions with the same average and variance. To see this figure in color, go online.